Riveter



J. C. HANNA June 17, 1930.

RIVETER Filed July 5, 1924 2 Sheets-Sheet l J. C. HANNA Iune 17, 1930.

RIVETER 2 Sheets-Sheet 2 Filed July 5, 1924 jiv Patented June 17, 1930 JOHN C. HAN'NA, OF CHICAGO, ILLINOIS I RIVETER Application med July 5, 1924. 'serial No. 724,232.

This invention relates to a new Vand improved riveter and moregparticularly'to a .riveter of this character in which a bell crank lever carries a rolling pin operating against an irregular cam surface. -f

Riveters of this type comprise a pair of jaw members Vpivotally connected together and having jaws adapted to engage the opposite endsof a rivet and to properly form it to 'rivetit in place. The movement of the jaws is lcause/d by the action ofalever carried by one of the jaw members and provided with means engaging a cam surface carried by the other jaw member. As the resistance of the rivet to the deformation caused by the riveting action varies during the action, it is desirable to provide a nonuniform closing movementof the riveting n jaws so as to give an ideal'pressure stroke of the riveting aws. This ideal pressure stroke approximates the deformation Aresistance 'of the rivet .which is minimum at beginning and maximum at completion. The pressure must always exceed the rivet resistance. This excess should be' the minimum which will result in deformation at practical speed, as any more available pressure entails the use of superfluous power. Itis further desired that the pressureV stroke shall attain to* maximum nearl its end and from this .point 'of attainment to the end ypressure shall be uniform. Various forms of' toggles will develop a Ypressure stroke somewhat similar to what is desired in the non-uniform part of theV ideal pressure stroke. Simple levers will develop what is desiredfin the uniform part of the ideal stroke near its end. The ideal stroke is unlike the stroke produced by either toggle or lever, but is graduated vfrom a minimum pressure at' start to a maximum pressure at about seven-eighths of its length, this maximum being maintained for the remaining one-eighth of length. This latter uniform pressure zone lof stroke is desirable as compensation y for irregularities in length of 'stroke as found in practice and as denite determination of the pressure on each rivet and thev strains in the riveting mechanism.

It is an object of the present invention t0,- provide a lever operated riveter havingl a lever operating between a pivoted center 'upon onej aw member and a cam surface of irregular contour carried by the other jaw member whereby an ideal pressure stroke is secured. p l

It is a further object to` provide a riveter of this typev in lwhich the cam engagingelement carried by the vlever is a rolling pin preferably mounted upon a roller bearing in the lever. i Y Y It is an additional object to provide con-- struction of this type in which the vrolling pin engages spaced camy Lmembers located upon opposite sides of the lever.

PATENT OFFICE i It is also an object to provide a riveter of this type in which the lever is pivotally mounted upon roller bearings carried upon one of the jaw members. l

Other and further objectswll appear asV the description proceeds. y

I have 'illustrated a preferred embodiment of my invention inV the vaccompairying drawings, in which- Figure lis a side elevationof the riveter, portions being broken away in order to show the construction;

Figure 2 is a horizontal section taken on line 2-2 of Figure 1';

Figure 3 is a view of Figure 1 as seen from the right; and' Figure 4 is a section taken on line Ll--l of Figure 1. y y

The riveter comprises the upper jawv member 11 and lower jaw member 12 which are pivotallyconnected together byy the pivot pin 13. vThe riveter iszpsupported by the hangers 14 which engage the pivot pin 13 andare connected to the bail 15. The hangers 14 are secured by means of thek stud 16 .be adjusted by means of the thread 19. The

lower die 2O is secured to the lower jaw in alignment with the upper die. The lever 21 is pivotally supported in the rear end 22 of the upper jaw member 11 upon the rollers 23 bearing upon pin 24. The upper end 25 of the lever is bifurcated and has secured theretothe piston rod 26 by means ofpin 26. The piston rod 26 is secured topiston 27 operating in cylinder 28. f The cylinder 28 is pivotally supported upon trunnions 29 carried in supporting lugs 30 extending upwardly from the upper jaw member 11. Supported upon thev endv` of the cylinder is the valve mechanism 3 1 which forms no partV of this invention 'and which need not be described in detail. This mechanism is adapted to selectively intro- Vduce fluid under pressure into the right hand end of the cylinder through pipe 32 or into the left hand end of the cylinder through pipe 33.

The lower end of the lever carries `the rolling pin 34 upon the roller bearing 35. This pin 34 extendsupon both sides of the lever and engages the upper cam surfaces `of the cam members 36 and 37. The guide disks 38 and 39 are secured to the opposite ends of the rolling pin 34 and engage the outer face of the cam members. Asshown in Figure 1, the cam members are secured to the lower jaw member by means'of bolts The lower end of the return rod. 41 passes through the block 42 'secured to the lower jaw member byy the bracket 42'. The Vlower end ofthe return rod carries the lock nut assembly 43 which limits its upward' movement. The upper portion of the return rod passes through an upper block 44 pivotally connected by means of bolt 44 to the return rod bracket 45. This bracket 45 is secured to the lever by means of Vbolts 46. yThe compression spring 47 surrounds the upper end of the return rod, its lower end engaging the upper return rod block and its upper end engaging the lock nut assembly 48.

The riveter is shown in Figure 1 with the riveting dies closed down upon the rivet. The lever is at its limit of counterclockwise movement. vThe cam blocks 36and37 are held againstthe rolling pin 34 by means of the return yrod 4l UQ itsassociate'd parts. The spring 47 yieldingly supports .the upper end of the return Vrod from the upper, return rod block which is secured tothe return rod block bracket which latter is secured to tl e lever. Thelower end of the return rod thus is drawnupwardly against theV lower return rod block.' Y

lVhen is desired to open the jawsthe fiuid under pressure is introduced'into'the left end of the cylinder 28 by vproper operation of the valve 31. A'Ihis operation it will be understood opens the right hand end to the atmosphere through pipe 32.

This iuid under pressure causes the piston 27 to move to the right carrying with it the piston rod 26. Through the action of the piston rod with upper portion 25 of the lever, the lever is rotated about its pivot in the clockwise direction. As the lever moves in this direction, the cam surfaces 36 and 37 are maintained in contact with the rolling pin 34. These surfaces are of such contour that during this clockwise .movement therear end of the lower jaw approaches the rear end ofl the upper jaw.

AConsequently the riveting dies are separated.

Vhen another Arivet to be operated upon is placed between the dies the lever is caused to move in the counter-clockwise direction by introducing `fluid under pressure through pipe 32 intothe right end ofthe cylinder 28 by means of suitable operation of valve 31. Due to the formation ofthe cam surfaces the roller 34 rolling Vdown `them causes the rear end of the jaw mem conditions as may come within the scope 'of the appended claims., Y

y I claim: f 1. In a riveter, a pair of pivoted. jaw members, a lever pivoted to one jaw .membelga pair of spaced parallel cam surfaces carried by the other jaw member, and en-v gaging means extending on opposite sides of thel vlever to engage the cam surfaces whereby the jaws are caused to move together. f v f' 2. In a riveter, a pair of jaw-'members pivoted together at an intermediate point, a lever pivoted to one jaw member, a cam carried by the other jaw member, said leverv carrying means adapted to engage the cam,

Vsaid lever having a portion extending above the rlrst jaw member, and an operating cylinder and piston pivotally supported from Y the first jaw member, .said piston being connected to the upper end of the lever.

3. In a riveter, ai pair of jaw members pivoted together at anV intermediate point, a lever pivoted to one jaw member, a cam carriedy by the other jawmember, said lever carrying means adapted to engage ther cam,

said lever having a portion extending away from the first jaw member, an operating cylinder and piston carried by the first jaw member, said piston being connected to the lever portion for operating the riveter, and means to normally urge the lever and cam carrying ends of the lever together, said,

means comprising a rod pivotally connected to one jaw and extending through a block pivotally supported 'by the upper jaw, a spring surrounding the rod above said jaw above the block and adjustable bearing means on the upper end of the rod.

Signed at Chicago, Illinois, this 28th day of June, 1924.

JOHN C. HANNA. 

